Devices for driving pins into masonry, structural members or the like



K. D'IEHL 3,399,817

STRUCTURAL Sept. 3, 1968 DEVICES Foa DRIVING PINS INT0 MAsoNRY,

MEMBERS oR THE LIKE Filed sept. I, 1965 Nq Nm Y I l I l H Ov mv N @E qqn mv MY ov United States Patent O 7 claims. (ci. 227-10) ABSTRACT F THEDISCLOSURE A device for driving pins into masonry or the like in which acartridge holder is arranged in a housing of the device movable from aninactive position to a cocked position upon insertion of a pin in themuzzle of the device and exertion of forward pressu-re on the latter,wherein a piston driven forwardly upon detonation of a charge in thecartridge holder drives the pin into the masonry, and wherein the pistonand elements of the device for Cooperating therewith are constructed andarranged to cooperate with each other to brake forward movement of thepiston with a force increasing during forward movement of the latter.

The invention relates to a device for driving pins into masonry,structural members or the like, having a housing, in the interior ofwhich there is accommodated a displaceable piston, which co-operateswith the pin to be introduced from the muzzle side, and a cartridgeholder, which is displaceable longitudinally land is situated spacedfrom a release mechanism when the device is in the uncocked position,and which can be transferred into a position of readiness for detonationby the pin bearing against the masonry or the like when the device iscocked upon exertion of forward pressure on the latter; the position ofreadiness for detonation remaining the same regardless of the length ofthe pin to be driven in. Such known devices for driving pins intomasonry have the advantage that the transfer into the position ofreadiness for detonation is only possible with a pin inserted.

It is the object of the invention to improve devices of the aforesaidkind, while retaining the advantages of known embodiments as outlined.According to the invention, this object is achieved essentially in thatan abutment on the pin serves to transfer the cartridge holder into theposition of readiness for detonation, preferably with the interpositionof a guide sleeve.

In the preferred embodiment of the invention, the abutment isconstructed in the form of a disc placed over the circumferential areaof the pin. In this case, it is advisable to hold the disc and/ or thepin by means of magnets let into the guide sleeve.

In devices for driving in pins, which are also called piston devices,the problem arises of dissipating the energy which is not used to drivein the pin, in the device itself, in such a manner that the device stillremains capable of operation and none of the parts of the device aredestroyed after only `a few cartridges have been fired. In theconstruction of such a device according to the invention, a step-by-stepdissipation of energy at various parts and points in the device isproposed, the individual stages becoming either wholly or only partiallyeffective depending on the material to be fired into. The rear end ofthe guide sleeve, which comes into operational communication with thecartridge store, is used as a first braking stage, and this end servesto brake the piston as it moves forwards. As a rule, this first brakingstage suffices to dissipate the energy not used to drive in the pin,when hard ICC materials such as steel, concrete or the like are firedat. On the other hand, if complete dissipation of the unused energy hasstill not been effected, for example when softer materials such ashollow building blocks are tired at, then one or more further brakingstages come into action.

If it is desired to achieve particularly strong braking, then accordingto a further proposal of the invention, the rear, reinforced region ofthe guide sleeve is constructed in the form of a member which can beexpanded by the piston striking against it. The expansion may beeffected in such a manner that the circumferential area of the expandedregion co-operates with inner walls of the housing so that a strongfriction occurs there. The expansion can be facilitated as a result ofthe fact that slits are provided in the rear zone of the guide sleeve sothat a plurality of expansible segments are formed. For example, fourexpansible segments, preferably of like formation, can be provided bymeans of two slits arranged crosswise for example.

The guide sleeve in the device according to the invention for driving inpins has a continuous bore in which the rear portion of the pin engagesfrom one side and a pin-shaped extension of the piston engages from theother side. Normally, the end face of the pin-shaped extension on theone hand and the head of the pin on the other hand are situated at adistance apart, and indeed a large gap is normally left between thesetwo parts. This has the decisive advantage that pins of different lengthcan easily be fired with the device according to the invention.

In the device according to the invention for driving in pins, it isadvisable to guide the guide sleeve in a protective cover which isconnected to a tubular cover by a circlip. The protective cover isdisplaceable by a short, fixed amount, in relation to the tubular cover.The purpose of this displacement is not adaptation to different lengthsof pin to be inserted but to compensate for irregularities on thesurface being fired into; in addition, the possibility is thus affordedof these parts of the device cooperating in the yielding motion of thedevice after the firing of a shot. The rear guide sleeve comprising thecartridge store, preferably comprises gas discharge ducts runningobliquely. These gas discharge ducts bring the combustion chamber intocommunication with a compartment which lies between the outer wall ofthe guide sleeve and parts of the inner wall of the housing. When aspecific distance has been covered by the piston during the firing of ashot, then the combustion chamber is vented as :a result. The gasesescaping through the gas discharge ducts act, at the same time, on therear outer breechblockmechanism parts of the device, so that these arealso at least partially used to take up the recoil.

Further `details of the invention are apparent from the followingspecific description.

Several examples of embodiments of the invention are illustrated in theaccompanying drawings in which:

FIG. l -shows a longitudinal section through the device aocording to theinvention for driving pins into masonry, in the uncooked condition;

FIG. 2, likewise in longitudinal section, shows the device of FIG. 1 butin the cocked position, with parts broken away;

FIG. 3 shows Aa further example of the -device according to theinvention, likewise with parts broken away, after the pin has beendriven in; and

FIG. 4 shows the ydevice of FIG. 3 in a position before the pin has beendriven in.

Mention may first be made of the fact that the release mechanism doesnot form part of the invention. Thus the embodiment of the releasemechanism on which the construction according to the example is basedserves only to demonstrate the mode of operation of the device. Theconstruction of this release mechanism is known per se; if necessary, itmay be replaced by other release mechanisms, likewise known. Only a fewparts of the release mechanism are therefore explained in the followingspeciic description.

The device for driving pins into masonry or the like has a protectivecover which is connected to a following tubular cover 11. The protectivecover 10 is displaceable by a short xed amount, in relation to thetubular cover 11. This slight displaceability of the said two parts isselected in order to compensate for irregularities on the surface beingtired into and to participate in the yielding movement of the deviceafter the tiring of the Shot. In order to receive the tubular cover 11,the protective cover 10 is provided with an annular groove which is opentowards the free end face and in which the free end of the tubular cover11 engages. In order to obtain the said displacement, two annulargrooves are provided, one of which is allocated to the protective cover10 and the other to the tubular cover 11. The two annular grooves 13 and14 co-operate with a circlip 12. The annular groove designated lby 13and allocated to the tubular cover 11 is adapted in width to the circlip12 so that this is received by the annular groove 13 so as to be heldagainst ydisplacement in the axial direction. The annular groove 14which is allocated to the protective cover 10 has a greater width incomparison. Thus it can be seen that a displacement of the protectivecover 10 in relation to the tubular cover 11 is possible in the axialdirection by an amount which corresponds to the difference in widthbetween the annular groove 13 and the annular groove 14. If necessary,the protective cover 10 and tubular cover 11 can be detached from oneanother. As can be seen from the figures of the drawings, the annular'groove 13 in the tubular cover 11 is deeper than the thickness of thecirclip 12. For detachment, the circlip 12 is pressed completely intothe annular groove 13, which is preferably effected from the outsidethrough apertures, not illustrated, in the protective cover 10. It isclear that the protective cover 10 can then be withdrawn from thetubular cover 11.

At the opposite end of the tubular cover 11 from the protective cover10, the tubular cover is connected to a breech ring 15. In the example,the connection is effected by means of a screw thread 16. Thisdetachable connection formed by the screw thread 16 can be used, forexample, when internal parts of the device have to be changed or if itis desired to clean the device.

The internal parts received by the protective cover 10, the tubularcover 11 and the breech ring 15 are: a front guide sleeve 17, a rearguide sleeve 18 and a piston 19.

The front guide sleeve 17 has a bore 20 which extends in thelongitudinal direction and has a uniform diameter throughout. On theother hand, the guide sleeve 17 has two regions which differ in externaldiameter. These are a front region designated yby 21 and having asmaller diameter and a rear region 22 of a larger dimeter. Both regions21 and 22 of the guide sleeve 17 are guided substantially against theinner rwall of the protective cover 10. The rear region 22 is receivedby a bore 24. The diameters of the respective regions 21 and 22 of theguide sleeve 17 on the one hand and the diameters of the 'bores 23 and24 of the protective cover 10 on the other hand are adapted to oneanother in such a manner that the guide sleeve 17 is received in theprotective cover 10, to be easily movable therein. The shoulders 25, 26,rwhich are formed as a result of the different diameters, are curvedwhen seen in cross-section, the shoulder 25 on the guide sleeve 17resembling a illet, while the shoulder 26 of the protective cover 10 isadapted to the shoulder 25 in such a manner that the shoulders 25 and 26can bear one against the other over their area.

The bore already mentioned in the guide sleeve 17 ends, at the inner endface of the guide sleeve 17 in a funnel-shaped widening 27 which is onlylow in height.

This co-operates with parts of the piston 19, as will be described indetail later. The opposite end, that is to say the end facing outwards,of the guide sleeve 17 is kept smooth, on the other hand. A plurality ofpermanent magnets 28, which extend in the same axial direction as thebore 20, are let into the region 21, their front end faces being flushwith the end face of the guide sleeve 17. The permanent magnets 28,which are mounted equidistant apart in the guide sleeve, serve to hold apin 29 which is received in the bore 20. The diameter of the head of thepin 29 corresponds substantially to the diameter of the bore 20 so thatthe pin 29 is guided at its rear end as a result. Guiding and holding atthe other end of the pin 29 is afforded by an abutment in form of a disc30. This is drawn over the shank of the pin 29 and lies with itscircumferential face against the inner wall of the bore 23 in theprotective cover 10. After the pin 29 has been pushed in, the magnets 28hold it firmly in position through the disc 30.

The rear guide sleeve 18 comprises various regions distinguished bydifferent diameters, not only inside its bore extending in thelongitudinal direction and generally designated by 31, but also at itsouter circumferential surface. The bore 31 is, on the one hand, adaptedto the piston 19, and on the other hand, one component region of itserves as a cartridge store 32. Over about two thirds of its length, thebore 31, beginning with its free front end, is kept uniform in diameter.This component region is designated by 33 and serves to guide thelongitudinally displaceable piston 19. The region having the largestdiameter, namely the guide region 34, of the piston 19, bears againsttheinner wall of the component region 33. At each side of the guideregion 34, the piston 19 has pin-like extensions 35, 36. The longer, 35,of the two, faces towards the muzzle of the device; its diametercorresponds substantially to that of the bore 20 in which it engagespartially, Its length is selected in such a manner that its front endface is remote from the head of the pin so that longer pins than thatillustrated can also be driven in. When the piston 19 is in its rearwardposition, the pin-like extension 36, situated on the other side of theguide region 34, projects into a portion 37 of the bore 31, the diameterof which is smaller than that of the bore 33. Thelength of the bore 37extends to shortly in front of the cartridge store 32. The space betweenthe cartridge store 32 and the bore 37 is constricted in diameter and isnot specifically designated.

As lalready mentioned, the rear guide sleeve 18 has a varied shape whichalso extends to its outer circumferential surface. Thus about two thirdsof the length of the guide sleeve 18 is tubular in shape and isdesignated by 38. The tubular portion 38 lies towards the front guidesleeve 17 and co-operates, by its end face, with the rear face of thefront guide sleeve 17 provided with the funnel-shaped widening 27. Asalready mentioned, the guide sleeve 18, which, like the guide sleeve 17,can be displaced longitudinally yby the same relatively small amount, isguided by its tubular portion 38 in the tubular cover 11. Furtherguiding of the `guide sleeve 18 is effected by means of a ange 39, whichis enlarged in diameter in relation to the other parts of this guidesleeve 18, against the inner wall of the breech ring 15. The shoulders,at each side of the flange 39, which are not separately designated,serve as stop surfaces and limit the displacement of the guide sleeve 18yin both directions. The one shoulder, namely that situated towards themuzzle of the device, co-operates `with the rear end face of the tubularcover 11, whereas the other co-operates with an encircling inward-facingextension on the breech ring 15. The rear region 40 of the rear guidesleeve 18 is somewhat smaller in its external diameter than the tubularportion 38. As can be seen from the figures of the drawings, the region40 receives the greater part of the bore 37, the cartridge store 32 andthe region having a constricted diameter situated between these twoparts. In the rear region of the rear guide sleeve 18 there are providedgas discharge ports 41 through which the combustion chamber is ventedafter the piston 19 has covered a certain distance, and at the same timethe rear outer parts of the breech mechanism are subjected to pressureand so partially used to intercept the recoil. In the example, the gasdischarge ducts 41 run, from the rear end of the bore 33, obliquelyoutwards, into a compartment which is bounded by the one shoulder of theflange 39, the rear portion of the guide sleeve 19 and by parts of thebreech ri-ng 15.

The release mechanism has a construction known per se. In the exampleselected, a so-called swing breech is illustrated the swing member beingdesignated by 42. The release mechanism further comprises a handle 43,which is likewise known, and a trigger 44. In addition, a lever isprovided, with which the opening of the device can be effected, forexample for the introduction of the cartridge.

The device constructed according to the invention, for driving pins intomasonry or the like, works as follows: The uncocked position of thedevice is illustrated in FIG. l of the drawing. From this it followsthat detonation of the cartridge is not yet possible in this position.This is only the case when the device is transferred into its positionof readiness -for detonation, which only occurs when the pin 29 isinserted correctly in the device.

At the commencement of work with the device according to the invention,the pin 29 with the disc 30 placed thereon, is inserted in the muzzle ofthe lbarrel. When the tip of the pin 29 is placed against the masonry,at that point where the pin is to be driven in, and then pressure isexerted on the device, in the direction of the masonry, then the deviceis transferred into the position of readiness for detonation, asillustrated in FIG. 2. From this it can be seen that the pin 29, bearingwith its tip against the masonry, has now been pushed completely intothe interior of the device. -In this position the disc 30, whichco-operates with the end face of the front Vguide sleeve 17, entrainsthe latter in the direction of the rear swing breech. The guide sleeve17 in turn displaces the rear guide sleeve 18 until this has reached itsposition of readiness for detonation. It is immediately obvious that, ifno pin has been inserted, or if the pin is not provided with a disc, itis impossible for the device to be taken into service. Great safety isachieved as a result.

It can further be seen from FIG. 2 that there is a large gap between thefront end face of the piston and the head of the pin 29. This means thatlonger pins than that illustrated can also be fired with the deviceaccording to the invention. When the release mechanism is actuated, withi the individual parts of the device for driving in pins in the positionshown in FIG. 2, then the piston 19 is displaced forwards by thehigh-pressure gases which develop, until it finally impinges, with itsfront end face, on the head of the pin 29 and drives this into themasonry.

During this forward movement of the piston 19, its shoulder impinges onthe widened region 22 of the rfront guide sleeve 17. Thus the firstbraking stage cornes into action. If the unused energy is still notdissipated in the first braking stage, for example because the pin isdriven into soft masonry, such as hollow building blocks, then a secondbraking stage cornes into action. This is a braking compartment lledwith compressible air.

If this braking stage is still not suflicient, co-operation occursbetween the annular shoulder 25- and a counter shoulder 26 during thejoint forward movement of the piston 19 and guide sleeve 17 (see FIG.2). The two cooperating shoulders are adapted to one another in such amanner that surface contact is obtained.

In order to obtain further braking, the protective cover 10 can bedisplaced in relation to the guide sleeve 17 by `an amount whichcorresponds substantially to the width of the circlip 12. Only after theupper edge of this guide means for the protective cover 10 has come tobear against the upper edge of the circlip, are the other parts of thedevice used to take up the excess energy.

Thus all the braking stages or only some of them come into action,depending on the material into which a pin has to be driven.

FIG. 3 of the drawings shows an embodiment of a device for driving pinsinto masonry or the like, which differs somewhat from that shown inFIGS. 1 and 2. In the rst place it should be noted that the front partof the guide sleeve, which is -now designated by 171, corresponds to theembodiment of the guide sleeve 17 already described so that no specialcomment is needed so far. The rear portion of the @guide sleeve 171 isdifferent in form, i.e., the thickened rear portion 46 of the guidesleeve 171 is constructed in the form of a brake member. The portion 46is divided into individual segments by slits which run in thelongitudinal direction. In the example, two crossed longitudinal slits48 are provided which divide the rear portion 46 into four segmentswhich are alike in shape. In the normal position, that is to say in theunbraked position, there is a wedge-like clearance 46 between the outersurface of the rear portion 46 of the guide sleeve 171 and the adjacentinner wall of the protective cover 10. This clearance clearly shown inFIG. 4 cannot be seen in FIG. 3 because the braked position isillustrated there. This means that the thickened rear portion 34 of thepiston has expanded the part 46 to such an extent that the outer surfacethereof is bearing against the inner wall of the protective cover as aresult of which braking is effected. In order to facilitate thisexpansion, the inner surfaces of the segments of the rear portion 46 hasa funnel-like recess 49 which co-operates with a shoulder orwedge-shaped portion 50 on the piston. The shoulder 5() is situated atthe transition point between the two parts 34 and 35 of the piston. AsFIG. 3 of the drawings shows, the transition point has inclined surfaceswhich are preferably adapted to those of the funnel wall. It should alsobe added that the rear portion 46 comprises an encircling externalIgroove 51 at the base of the slits 48. The primary purpose of this isto provide a weakened cross-section in such a manner that the individualsegments can be more easily bent out of their inoperative position andtransferred into their operative position, that is to say their brakingposition.

As already mentioned, the embodiments illustrated are only examples ofconstruction of the invention which is not restricted thereto. Indeed,many other embodiments and applications are possible. For example, theprotective cover 10 may have a different form. For example it may be oftwo-part construction and may possibly be provided with an additionalouter cover consisting of a resilient material. Furthermore, both theguide sleeves and the piston may be Igiven a construction other thanthat illustrated. And finally other pins, known per se, may be used withthe device according to the invention.

I claim:

1. A device for driving pins into masonry or the like comprising, incombination, elongated housing means having a front end and a rear end;a firing mechanism connected to said rear end of said housing means;elongated guide sleeve means having a front end and a rear end forming acartridge holder and being slidably guided in said housing means betweena forward inactive position in which said cartridge holder is spacedfrom said ring mechanism and in which said front end of said guidesleeve means is rearwardly spaced a given distance from said front endof said housing and a rearwardly displaced cocked position ready tocooperate with said firing mechanism; said guide sleeve means beingadapted to be engaged by a portion of a pin inserted through said frontend thereof while the front end of the pin projects beyond said frontend of said housing means in such a manner so that upon exertion offorward pressure on said housing means, said guide sleeve means is movedfrom said inactive to said cocked position in which said front end ofsaid guide sleeve means is rearwardly spaced from said front end of saidhousing means a distance greater than said given distance whereby thedevice may be fired only when after insertion of a pin a rearwardpressure is exerted on the latter; and a piston slidably guided in saidguide sleeve means forwardly of said cartridge holder and having a freefront end spaced from said front end of the guide sleeve means such adistance so that pins of different lengths may be inserted in said guidesleeve means in engagement with said guide sleeve means while the rearend of said pin is still spaced from said free front end of said piston.

2. A device as defined in claim 1, wherein said guide sleeve meanscomprises a front guide sleeve and a rear guide sleeve having at a frontportion thereof adjacent said front guide sleeve a larger inner diameterthan thev latter, and wherein said piston has in said portion of saidrear guide sleeve a piston portion of a diameter substantially equal tothe inner diameter of the latter and a length considerably shorter thanthat of said rear guide sleeve, and a forwardly extending coaxialelongation of a diameter substantially equal to the inner diameter ofsaid front guide sleeve and extending into the latter to be slidablyguided therein.

3. A device as defined in claim 2, wherein said housing means is tubularand wherein a front portion of said housing means has a smaller innerdiameter than the rear portion thereof, and wherein said front guidesleeve has a rear portion slidably guided in said rear portion of saidhousing means and a front portion slidably guided in said front portionof said housing means, said rear portion of said front guide sleevebeing in said cocked postion rearwardly spaced from said front portionof said housing means so as to form in said cocked position an enclosedair chamber between the front end of said rear portion of said frontguide sleeve and the rear end of said front portion of said housingmeans.

4. A device as defined in claim 2, wherein said rear guide sleeve has arear portion of an inner diameter smaller than said diameter of saidfront portion of said rear guide sleeve so as to form a shoulder at thejunction of said rear portion and said front portion of said rear guidesleeve, and at least one passage leading from said shoulder rearwardlyand ending at the peripheral outer surface of said rear guide sleeve,and wherein said piston has a rearward extension slidably guided in saidrear portion of said rear guide sleeve so that when a charge isdetonated in said cartridge holder the combustion gases may escapethrough said passage after the rear end of said rear extension of saidpiston has passed said shoulder.

5. A device as defined in claim 3, wherein said front guide sleeve hasat the rear end thereof at least two resiliently bendable portionshaving outer surfaces spaced from the inner surface of said housingmeans and inner surfaces forming between themselves a funnel-shapedspace tapering toward the front end of said front guide sleeve, andwherein said elongation of said piston has a wedge-shaped portionmovable into said funnel-shaped space during forward movement of saidpiston to cooperate with said resiliently bendable portions to press theouter surfaces thereof into engagement with said inner surface of saidhousing means.

6. A device as defined in claim 3, wherein said tubular housing meanscomprises a pair of telescoping portions, and means cooperating withsaid telescoping portions for limiting relative movement thereof so thatin said inactive position of said guide sleeve means said front endthereof will always be located rearwardly of said front end of saidhousing means.

7. A device as defined in claim 1, and including at least one magnet inthe region of the front end of said elongated guide' sleeve means andadapted to cooperate with a pin of magnetizable material inserted insaid guide sleeve means to hold the pin by magnetic force in said guidesleeve means.

References Cited UNITED STATES PATENTS 2,632,890 3/1953 Tietig 227-103,203,609 8/1965 Diehl 227-10 XR 3,239,121 3/1966 Kopf et al. 227-103,319,862 5/1967 Neighorn 227-10 WILLIAM W. DYER, I R., PrimaryExaminer.

R. L. FARRIS, Assistant Examiner.

